I was just checking out some info on a couple of websites and got some confirmation on what I thought I remembered from my studies:

According to an item in Carve Magazine, Spring '98, pissing your wetsuit could be dodgy in the wrong locations. It reads as follows:

Pissing your wetsuit can have fatal consequences if you surf in sharky waters, according to an Australian marine biologist. David Baxter from Sydney, who has studied sharks for 15 years, claims that most attacks occured shortly after the victims had urinated in the water.

"Surfers and swimmers think their urine will be swept away faairly quickly, but it stays it the wetsuit and creates a powerful smell for sharks. Sharks have well-developed olfactory glands intheir noses and are attracted to the smell of body fluids such as blood and urine."

And another quote here:

The shark smells this and many documentaries have shown me that sharks sense this smell and immediately think a free feed is available as urine indicates an animal in distress. A common response by animals for shock and near death. Not enough is said about urinating in the ocean and I never do soley for that reason and it can damage the wetsuit. Sharks are known to be in a beach and go straight for the person who has urinated missing hundreds of other beach goers sensing the smell and hunting it down."